Copper alloy wire rod and method for manufacturing the same

Abstract

A copper alloy wire rod includes a copper parent phase and short fiber-shaped composite phases which are dispersed in the copper parent phase and which contain Cu 8 Zr 3 and Cu, wherein the content of Zr is within the range of 0.2 atomic percent or more and 1.0 atomic percent or less. This copper alloy wire rod can be obtained by including the steps of melting a raw material in such a way that a copper alloy having a Zr content within the above-described range of is produced so as to obtain a molten metal in a melting step, casting the molten metal so as to obtain an ingot in a casting step, and subjecting the ingot to cold wire drawing in a wire drawing step, wherein the wire drawing step and a treatment after the wire drawing step are performed at lower than 500° C.

What is claimed is: 
     
       1. A copper alloy wire rod comprising a copper parent phase and short fiber-shaped composite phases which are dispersed in the copper parent phase and which contain Cu 8 Zr 3  and Cu,
 wherein the copper alloy contains Zr within a range of 0.2 atomic percent or more and 1.0 atomic percent or less, 
 wherein the composite phase has a length L in the wire drawing direction and a length T in the direction orthogonal to the wire drawing direction, which satisfy 1.5≦L/T<17.9, 
 wherein the copper alloy wire rod has an electrical conductivity of 70% IACS or more and a tensile strength of 700 MPa or more, and 
 wherein the copper alloy is a binary alloy. 
 
     
     
       2. The copper alloy wire rod according to  claim 1 , wherein an area ratio of the composite phases is 0.5% or more and 5.0% or less. 
     
     
       3. The copper alloy wire rod according to  claim 1 , wherein the composite phase has a length L in the wire drawing direction and a length T in the direction orthogonal to the wire drawing direction, which satisfy 1.5≦L/T<10.0. 
     
     
       4. A method for manufacturing a copper alloy wire rod comprising:
 a melting step of melting a raw material of a copper alloy having a Zr content within the range of 0.2 atomic percent or more and 1.0 atomic percent or less to obtain a molten metal; 
 a casting step of casting the molten metal so as to obtain an ingot; and 
 a wire drawing step of subjecting the ingot to a cold wire drawing performed at lower than 500° C. and a treatment after the cold wire drawing performed at lower than 500° C.; 
 wherein the copper alloy wire rod comprises a copper parent phase and short fiber-shaped composite phases which are dispersed in the copper parent phase and which contain Cu 8 Zr 3  and Cu, 
 wherein the composite phase has a length L in the wire drawing direction and a length T in the direction orthogonal to the wire drawing direction, which satisfy 1.5≦L/T<17.9, 
 wherein the copper alloy wire rod has an electrical conductivity of 70% IACS or more and a tensile strength of 700 MPa or more, and 
 wherein the copper alloy is a binary alloy. 
 
     
     
       5. The method for manufacturing a copper alloy wire rod according to  claim 4 , wherein the wire drawing step is performed with a degree of wire drawing η of 5.0 or more and 12.0 or less. 
     
     
       6. The method for manufacturing a copper alloy wire rod according to  claim 4 , wherein the treatment is a strain relief treatment that is performed at a temperature higher than the temperature of the cold wire drawing and lower than 500° C. for a period of 1 second or more and 60 seconds or less.